An important factor affecting the mortality rate among newborn animals is the presence of immunoglobulins among the newborn's physiological components. Immunoglobulins, in general, ward off illness and disease, and they must be present above certain threshold quantities in order to effectively function. Specifically, immunoglobulins are protein molecules by which the body defends itself against diseases. Due to the importance of mammalian immunoglobulins in the diagnosis, treatment and control of diseases, various qualitative and quantitative tests have been developed. Those in current use include the refractometer which estimates the total protein; sulfates and sulfites which assess the total globulin; electrophoresis which measures the total immunoglobulin; and radial immunodiffusion which assesses one type of immunoglobulin molecule at a time along with the various serological tests which measure the specific antibodies. Typically, the tests referred to are laborious and require the use of expensive laboratory instruments as well as highly trained personnel.
The primary source of immunoglobulins for the newborn is colostrum which, of course, is furnished by the animal's mother during nursing. Unfortunately, these nursing products often do not contain sufficient quantities of immunoglobulins to meet or exceed the threshold requirements. Unless these deficiencies are noted early during the first few hours in the newborn's life, and the diet is supplemented with appropriate additives, the newborn can succumb to illness or disease. Unfortunately, there is no simple test for assessing immunoglobulin levels in colostrum, milk or their whey under field and laboratory conditions.
Again, present techniques for detection of such deficiencies usually require rather sophisticated equipment, extended time periods, and body fluids which only are indirectly available (e.g., through centrifugation and separation) from the animal sample to be tested. Previously, aldehydes, such as, glutaraldehyde have been employed as reagents in testing immunoglobulin levels in serum. However, attempts to employ aldehydes in testing immunoglobulin levels in body fluids, such as, blood and plasma which have not been broken down into components of the fluids have been unsuccessful, principally because the aldehydes have not been used in sufficient concentrations to act as an anticoagulant and this was not known prior to my invention. Because of these limitations, it has been impractical in the past to perform the tests, especially if the newborns are, for example, farm animals that cannot be conveniently taken to a veterinary hospital or cannot be tested at the site of birth or sale; and without testing can result in death. Representative approaches which have been taken in the past are disclosed in U.S. Pat. No. 3,912,610 to Lou and which is directed to the use of a dilute glutaraldehyde in electroquantitative determination of proteins. The rate of reaction of dilute glutaraldehyde with immunoglobulins for assessing immunoglobulins in the serum of various animals is discussed in an article entitled "Use of the Glutaraldehyde Coagulation Test for Detection of Hypogammaglobulinemia in Neonatal Calves", by Tennant, B., DVM; JAVMA, Vol. 174, No. 8, Apr. 15, 1979.
A need exists for a simple convenient method and reagent which can be used in the field or in the laboratory for the determination of the presence of adequate immunoglobulin levels in samples from newborn animals and humans or in the food which they ingest and which method can be practiced and levels tested without the requirement of specialized knowledge or medical expertise. Unlike this invention which is useful in identifying and correcting the problem, past methods are technically limited to diagnosis in the laboratory or hospital.